Well that didn't take long. Despite the song only being announced yesterday,"I am Murloc" has been 5-starred on Expert, and you can see the video above to prove it. You can also see the notes they've chosed -- as a veteran of all three Guitar Hero games (and a current owner of Rock Band, though "Green Grass" is giving me trouble on Expert), I have to say that it looks pretty simple, especially compared to some of the other songs in GH3. It is too bad that they used the normal Guitar Hero 3 singer, too, and not a virtual version of Samwise.
If you want something a little tougher, head down after the jump to see a hacked custom version of "I am Murloc" for Guitar Hero 2. The phrasing on that one seems to fit much more, and it seems to work a little better than the official version that got released in the latest game.